You can change the visibility of an element in CSS using the `visibility` property. This property can take several values:
- `visible`: This is the default value which makes an element visible.
- `hidden`: This hides an element but it will still take up the same space as before. The element will be hidden, but space for it will be kept.
- `collapse`: This is used for table elements and it will remove a row or column, but it will not affect the table layout. The space taken up by the row or column will be available for other content.
Here is an example:
```
div {
visibility: hidden;
}
```
This will hide the `div` element on the page.
If you want to completely remove the element, including the space it takes up, use the `display: none;` property and value.
```
div {
display: none;
}
```
This will hide the `div`, and it will no longer occupy any space on the page.
